สอบถามเรื่องการ Check ค่าก่อน Add row datagridview ครับ

if (!Found && txtqty <= Convert.ToInt32(DB_Reader.GetString("stock")))
                            {
                                //Add the row to grid view
                                dataGridView1.Rows.Add(DB_Reader.GetString("product_barcode"), DB_Reader.GetString("product_name"), txtqty, txtSum);
                                this.textBox1.Text = "";
                                this.textEdit4.Text = "1";
                            }
                        }
                        else
                        {
                            if (txtqty <= Convert.ToInt32(DB_Reader.GetString("stock")))
                            {
                                //Add the row to grid view for the first time
                                dataGridView1.Rows.Add(DB_Reader.GetString("product_barcode"), DB_Reader.GetString("product_name"), txtqty, txtSum);
                                this.textBox1.Text = "";
                                this.textEdit4.Text = "1";
                            }

if (DB_Reader.HasRows)
                    {
                        //Boolean to check if he has row has been
                        bool Found = false;
                        if (dataGridView1.Rows.Count > 0)
                        {
                            //Check if the product Id exists
                            foreach (DataGridViewRow row in dataGridView1.Rows)
                            {
                                if (Convert.ToString(row.Cells[0].Value) == textBox1.Text && txtqty + Convert.ToInt16(row.Cells[2].Value) <= Convert.ToInt32(DB_Reader.GetString("stock")))
                                {
                                    //Update the Quantity of the found row
                                    row.Cells[2].Value = Convert.ToString(txtqty + Convert.ToInt16(row.Cells[2].Value));
                                    row.Cells[3].Value = Convert.ToInt16(row.Cells[2].Value) * Convert.ToDecimal(DB_Reader.GetString("sale_price"));
                                    Found = true;
                                    this.textBox1.Text = "";
                                    this.textEdit4.Text = "1";
                                }
                            }
                            if (!Found && txtqty <= Convert.ToInt32(DB_Reader.GetString("stock")))
                            {
                                //Add the row to grid view
                                dataGridView1.Rows.Add(DB_Reader.GetString("product_barcode"), DB_Reader.GetString("product_name"), txtqty, txtSum);
                                this.textBox1.Text = "";
                                this.textEdit4.Text = "1";
                            }
                        }
                        else
                        {
                            if (txtqty <= Convert.ToInt32(DB_Reader.GetString("stock")))
                            {
                                //Add the row to grid view for the first time
                                dataGridView1.Rows.Add(DB_Reader.GetString("product_barcode"), DB_Reader.GetString("product_name"), txtqty, txtSum);
                                this.textBox1.Text = "";
                                this.textEdit4.Text = "1";
                            }
                        }